Add test for the NetworkTraceHandler
This tests the logic of converting bpf PacketTraces into Perfetto
TracePackets. The test stands up an in-process trace and parses the
resulting trace output (filtering to only the events we care about).
On the implementation side, `Write` is added as a non-static method
to do the conversion from a batch of PacketTraces. Because this becomes
part of the instance, per-instance configuration (e.g. interning) can be
applied without causing conflicts between concurrent sessions.
Bug: 246985031
Test: atest libnetworkstats_test
Change-Id: I15a26ba720eff308d01e6827a176a6b2f7c60e80
diff --git a/service-t/native/libs/libnetworkstats/Android.bp b/service-t/native/libs/libnetworkstats/Android.bp
index f2c569f..f40d388 100644
--- a/service-t/native/libs/libnetworkstats/Android.bp
+++ b/service-t/native/libs/libnetworkstats/Android.bp
@@ -62,6 +62,7 @@
header_libs: ["bpf_connectivity_headers"],
srcs: [
"BpfNetworkStatsTest.cpp",
+ "NetworkTraceHandlerTest.cpp",
"NetworkTracePollerTest.cpp",
],
cflags: [
@@ -74,6 +75,8 @@
"libgmock",
"libnetworkstats",
"libperfetto_client_experimental",
+ "libprotobuf-cpp-lite",
+ "perfetto_trace_protos",
],
shared_libs: [
"libbase",
diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
index 07f8054..cd62bc5 100644
--- a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
@@ -59,10 +59,12 @@
// static
NetworkTracePoller NetworkTraceHandler::sPoller(
[](const std::vector<PacketTrace>& packets) {
+ // Trace calls the provided callback for each active session. The context
+ // gets a reference to the NetworkTraceHandler instance associated with
+ // the session and delegates writing. The corresponding handler will write
+ // with the setting specified in the trace config.
NetworkTraceHandler::Trace([&](NetworkTraceHandler::TraceContext ctx) {
- for (const PacketTrace& pkt : packets) {
- NetworkTraceHandler::Fill(pkt, *ctx.NewTracePacket());
- }
+ ctx.GetDataSourceLocked()->Write(packets, ctx);
});
});
@@ -92,6 +94,13 @@
mStarted = false;
}
+void NetworkTraceHandler::Write(const std::vector<PacketTrace>& packets,
+ NetworkTraceHandler::TraceContext& ctx) {
+ for (const PacketTrace& pkt : packets) {
+ Fill(pkt, *ctx.NewTracePacket());
+ }
+}
+
// static class method
void NetworkTraceHandler::Fill(const PacketTrace& src, TracePacket& dst) {
dst.set_timestamp(src.timestampNs);
diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
new file mode 100644
index 0000000..2318da5
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <vector>
+
+#include "netdbpf/NetworkTraceHandler.h"
+#include "protos/perfetto/trace/android/network_trace.pb.h"
+#include "protos/perfetto/trace/trace.pb.h"
+#include "protos/perfetto/trace/trace_packet.pb.h"
+
+namespace android {
+namespace bpf {
+using ::perfetto::protos::NetworkPacketEvent;
+using ::perfetto::protos::Trace;
+using ::perfetto::protos::TracePacket;
+using ::perfetto::protos::TrafficDirection;
+
+// This handler makes OnStart and OnStop a no-op so that tracing is not really
+// started on the device.
+class HandlerForTest : public NetworkTraceHandler {
+ public:
+ void OnStart(const StartArgs&) override {}
+ void OnStop(const StopArgs&) override {}
+};
+
+class NetworkTraceHandlerTest : public testing::Test {
+ protected:
+ // Starts a tracing session with the handler under test.
+ std::unique_ptr<perfetto::TracingSession> StartTracing() {
+ perfetto::TracingInitArgs args;
+ args.backends = perfetto::kInProcessBackend;
+ perfetto::Tracing::Initialize(args);
+
+ perfetto::DataSourceDescriptor dsd;
+ dsd.set_name("test.network_packets");
+ HandlerForTest::Register(dsd);
+
+ perfetto::TraceConfig cfg;
+ cfg.add_buffers()->set_size_kb(1024);
+ cfg.add_data_sources()->mutable_config()->set_name("test.network_packets");
+
+ auto session = perfetto::Tracing::NewTrace(perfetto::kInProcessBackend);
+ session->Setup(cfg);
+ session->StartBlocking();
+ return session;
+ }
+
+ // Stops the trace session and reports all relevant trace packets.
+ bool StopTracing(perfetto::TracingSession* session,
+ std::vector<TracePacket>* output) {
+ session->StopBlocking();
+
+ Trace trace;
+ std::vector<char> raw_trace = session->ReadTraceBlocking();
+ if (!trace.ParseFromArray(raw_trace.data(), raw_trace.size())) {
+ ADD_FAILURE() << "trace.ParseFromArray failed";
+ return false;
+ }
+
+ // This is a real trace and includes irrelevant trace packets such as trace
+ // metadata. The following strips the results to just the packets we want.
+ for (const auto& pkt : trace.packet()) {
+ if (pkt.has_network_packet()) {
+ output->emplace_back(pkt);
+ }
+ }
+
+ return true;
+ }
+
+ // This runs a trace with a single call to Write.
+ bool TraceAndSortPackets(const std::vector<PacketTrace>& input,
+ std::vector<TracePacket>* output) {
+ auto session = StartTracing();
+ HandlerForTest::Trace([&](HandlerForTest::TraceContext ctx) {
+ ctx.GetDataSourceLocked()->Write(input, ctx);
+ ctx.Flush();
+ });
+
+ if (!StopTracing(session.get(), output)) {
+ return false;
+ }
+
+ // Sort to provide deterministic ordering regardless of Perfetto internals
+ // or implementation-defined (e.g. hash map) reshuffling.
+ std::sort(output->begin(), output->end(),
+ [](const TracePacket& a, const TracePacket& b) {
+ return a.timestamp() < b.timestamp();
+ });
+
+ return true;
+ }
+};
+
+TEST_F(NetworkTraceHandlerTest, WriteBasicFields) {
+ std::vector<PacketTrace> input = {
+ PacketTrace{
+ .timestampNs = 1000,
+ .length = 100,
+ .uid = 10,
+ .tag = 123,
+ .ipProto = 6,
+ .tcpFlags = 1,
+ },
+ };
+
+ std::vector<TracePacket> events;
+ ASSERT_TRUE(TraceAndSortPackets(input, &events));
+
+ ASSERT_EQ(events.size(), 1);
+ EXPECT_THAT(events[0].timestamp(), 1000);
+ EXPECT_THAT(events[0].network_packet().length(), 100);
+ EXPECT_THAT(events[0].network_packet().uid(), 10);
+ EXPECT_THAT(events[0].network_packet().tag(), 123);
+ EXPECT_THAT(events[0].network_packet().ip_proto(), 6);
+ EXPECT_THAT(events[0].network_packet().tcp_flags(), 1);
+}
+
+TEST_F(NetworkTraceHandlerTest, WriteDirectionAndPorts) {
+ std::vector<PacketTrace> input = {
+ PacketTrace{
+ .timestampNs = 1,
+ .sport = htons(8080),
+ .dport = htons(443),
+ .egress = true,
+ },
+ PacketTrace{
+ .timestampNs = 2,
+ .sport = htons(443),
+ .dport = htons(8080),
+ .egress = false,
+ },
+ };
+
+ std::vector<TracePacket> events;
+ ASSERT_TRUE(TraceAndSortPackets(input, &events));
+
+ ASSERT_EQ(events.size(), 2);
+ EXPECT_THAT(events[0].network_packet().local_port(), 8080);
+ EXPECT_THAT(events[0].network_packet().remote_port(), 443);
+ EXPECT_THAT(events[0].network_packet().direction(),
+ TrafficDirection::DIR_EGRESS);
+ EXPECT_THAT(events[1].network_packet().local_port(), 8080);
+ EXPECT_THAT(events[1].network_packet().remote_port(), 443);
+ EXPECT_THAT(events[1].network_packet().direction(),
+ TrafficDirection::DIR_INGRESS);
+}
+
+} // namespace bpf
+} // namespace android
diff --git a/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h b/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
index bdc18fb..9520d7b 100644
--- a/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
+++ b/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
@@ -46,6 +46,11 @@
void OnStart(const StartArgs&) override;
void OnStop(const StopArgs&) override;
+ // Writes the packets as Perfetto TracePackets, creating packets as needed
+ // using the provided callback (which allows easy testing).
+ void Write(const std::vector<PacketTrace>& packets,
+ NetworkTraceHandler::TraceContext& ctx);
+
private:
// Convert a PacketTrace into a Perfetto trace packet.
static void Fill(const PacketTrace& src,